What was found
ON CONFIGURING FOR LANDING, WHEN SELECTING FLAP 30 FROM TE DISPLAY, EICAS MSG APPEARED. RAN QRH PROCEDURE & LANDED FLAP 20 DEGREE. RAN THE FLAP HYD FROM 0 TO 30 DEGREES 2 TIMES, RAN THE FLAPS ELEC 0 TO 30, 2 TIMES WITH NO FAULTS. CHECKED ALL 3 FSEU'S NO FAULTS IAW MM 27-00-5-0, FIM 27-51 TREE 803. RT INBD FLAP, INBD JACKSCREW THREADS ROUGH & BALL NUT SEALS BROKEN. REF WRI 27-50 3523 FOR REPLACEMENT, RII & PARTS INFO. FLAP SYS LUBED & XMSN GEARBOXES SERVICED. TORQUE BRAKES CHECKED GOOD. REF WRI 27-50 3517 FOR WORK ACCOMPLISHED. OK FOR SERVICE.